The present invention relates to a bulb-form lamp and its manufacturing method.
In a conventional bulb-form lamp, for example, a bulb-form fluorescent lamp, an enclosure 15 comprising a globe 1 and a case 14 has accommodated therein a fluorescent tube 4, a lighting circuit 16 for lighting the fluorescent tube 4, and two lead wires 17a and 17b connected to the lighting circuit 16 to supply power, as shown in FIG. 4.
The case 14 has a base 18 screwed at an end portion thereof.
The lighting circuit 16 has a lighting part 16b mounted on a printed circuit board 16a. The printed circuit board 16a is located inside the case 14 perpendicularly to a center axis thereof.
The base 18 has a screw-like shell 18a and an eyelet 18c provided at an end portion of the shell 18a via an insulator 18b comprising glass.
Individual parts of the shell 18a and eyelet 18c are embedded in the insulator 18b to integrate the shell 18a, the insulator 18b, and the eyelet 18c together.
One 17a of the lead wires is soldered outside the base 18, that is, to an outer surface of the eyelet 18c. Alternatively, the lead wire 17a and the eyelet 18c are connected together by means of plasma arc welding for environmental reasons.
A method for manufacturing this conventional bulb-form lamp will be described below.
A normal method is used to assemble together the enclosure 15, the fluorescent tube 4, and the lighting circuit 16 having the lead wires 17a and 17b connected thereto. Subsequently, the base 18 is screwed on an end portion of the case 14 and then caulked and fixed to the case 14. In this case, the lead wire 17a is led out from a through-hole 18d formed in the eyelet 18c. The led-out portion of the lead wire 17a is fixedly soldered to an outer surface of the eyelet 18c. 
In this conventional bulb-form lamp, however, since the lighting circuit 16 and the eyelet 18c are connected together by means of the lead wire 17a, material costs of the lead wire 17a are high and a large amount of time and labor is required to connect the lead wire 17a to the lighting circuit 16 and the eyelet 18c, thereby reducing productivity and increasing costs.
In addition, if the lead wire 17a of the conventional bulb-frame lamp is connectedly soldered to the eyelet 18c, a flux (a resin or the like) used for the soldering is formed into a film on a surface of the solder, so that when this base 18 is attached to a socket of lighting equipment (not shown), the eyelet 18c and the socket are inappropriately contacted with each other. In addition, corrosion of the eyelet 18C by this flux will cause an inappropriate contact between the eyelet 18C and the socket. Such an inappropriate contact may lead to a lighting failure.
In addition, if plasma arc welding is used to connect the lead wire 17a to the eyelet 18c, an apparatus for plasma arc welding is expensive and requires a large installation space as well as high costs due to the needs for time and labor required to maintain and manage the apparatus.
The present invention is provided to solve these problems, and it is an object thereof to provide a bulb-form lamp that allows a lighting circuit and an eyelet to be easily and reliably connected together without using any soldering or plasma arc welding or lead wires, that prevents a lighting failure caused by an inappropriate contact, and that requires low costs while providing a high productive efficiency, as well as a method for manufacturing this bulb-form lamp.
A bulb-form lamp according to the present invention is configured so that a case having a lighting circuit accommodated inside includes a base formed at an end portion thereof and having an eyelet and a screw-like shell and so that the lighting circuit and the eyelet are connected together without any lead wire.
Alternatively, the present invention provides a method for manufacturing a bulb-form lamp in which a case having a lighting circuit accommodated inside includes a base formed at an end portion thereof and having an eyelet and a screw-like shell and in which the eyelet is directly mounted on a printed circuit board of the lighting circuit, the method comprising mounting the eyelet on the printed circuit board of the lighting circuit and then inserting the lighting circuit with the eyelet mounted thereon into the case to fit the eyelet into an eyelet receiving section provided at an end portion of the case.
The above described bulb-form lamp and its manufacturing method enable the lighting circuit and the eyelet to be easily and reliably connected together without using soldering or plasma arc welding or lead wires. In addition, the omission of the soldering or plasma arc welding process serves to improve productive efficiency. Management costs of facilities required for soldering or plasma arc welding and the number of, for example, lead wire materials are also reduced to diminish the total cost. Further, soldering is not particularly required, thereby restraining fluxes to prevent an inappropriate contact between the eyelet and the lighting equipment.
Moreover, the present invention provides a method for manufacturing a bulb-form lamp in which a case having a lighting circuit accommodated inside includes a base formed at an end portion thereof and having an eyelet and a screw-like shell and in which the eyelet shaped like a push pin is connected to a screwless terminal mounted on a printed circuit board of the lighting circuit, the method comprising mounting the screwless terminal on the printed circuit board of the lighting circuit, then inserting the lighting circuit with the screwless terminal mounted thereon into the case for fixture , and then fitting the eyelet into an eyelet receiving section provided at an end portion of the case to connect the eyelet to the screwless terminal.
The above described manufacturing method enables the lighting circuit and the eyelet to be easily and reliably connected together without using soldering or plasma arc welding or lead wires. In addition, the omission of the soldering or plasma arc welding process serves to improve productive efficiency. Management costs of facilities required for the soldering or plasma arc welding process and the number of, for example, lead wire materials are also reduced to diminish the total cost. Further, soldering is not particularly required, thereby restraining fluxes to prevent an inappropriate contact between the eyelet and the lighting equipment. Furthermore, when the base is plugged into the socket and even if the eyelet is pushed toward an interior of the case, a head section of the eyelet comes in abutment with an outer surface of the eyelet receiving section to prevent the eyelet from entering the interior of the case.